1. Field of the Invention
This invention relates in general to carts and in particular to carts for the replacement of modules.
2. Description of the Related Art
Gas laser systems, such as excimer lasers, conventionally include a laser chamber or discharge chamber. A mixture of gases (such as halogen, rare gases, helium, and neon) are injected into the chamber and excited by a potential between two electrodes to produce a laser beam.
One problem with such a laser system is that the laser chamber must be serviced regularly. With some laser chambers weighing over 140 pounds, removing the laser chamber from the laser system housing or installing the laser chamber in the housing can be physically challenging for service technicians. In addition, the weight of the chamber may exceed some organizations handling regulations.
Another problem with such a laser system is that changing out an existing laser chamber with a new laser chamber can be cumbersome. Because manufactures desire limiting equipment down time, it is sometimes preferable to install a new laser chamber almost immediately after the old one is removed. However, because the existing laser chamber must be removed before a new chamber can be installed, adequate space for two laser chambers must be available in the vicinity of the laser system housing. Furthermore, unless a cart is capable of handling two laser chambers, the existing chamber would be required to rest on the ground before the new one is installed. Placing a chamber or other laser system module on the ground during a changeout requires the lifting of the existing laser chamber up to the cart to be hauled away.
What is desirable is a system to reduce the manual effort and increase the convenience in installing or removing a laser chamber or other types of laser system modules in a laser system housing.
A cart is disclosed which advantageously reduces the manual effort in installing or removing a laser chamber from a laser system housing.
In one aspect, the invention includes a method for changing out a laser system module. The method includes removing a first laser system module from a housing to a first platform of a cart at a first elevation and moving the first platform with the first laser system module to a second elevation. The method also includes moving a second platform with a replacement laser system module of the cart to approximately the first elevation and removing the replacement laser system module from the second platform to the housing.
In another aspect, the invention includes a cart for the transportation of laser system modules to or from a laser system housing. The cart includes a frame, a first platform, and a second platform located above the first platform. The first platform is vertically movable with respect to the frame to a first elevation for a transfer of a laser system module between the first platform and the laser system housing. The second platform is vertically movable to the first elevation for a transfer of a laser system module between the second platform and the laser system housing.
In another aspect of the invention, a cart includes a frame, a first platform, and a second platform located above the first platform. The second platform is coupled to the first platform such that an upward force for a vertical movement of the second platform with respect to the frame provides a vertical movement of the first platform with respect to the frame at an elevated position. The first platform is vertically movable with respect to the frame to a first elevation for the placement or removal of objects with respect to the first platform. The second platform is vertically movable to the first elevation for the placement or removal of objects with respect to the second platform.
In another aspect, the invention includes a cart for carrying laser system modules. The cart includes a first wheel base including wheels. The cart is rollable along a surface on the wheels of the first wheel base. The cart includes a second wheel base including wheels. The cart is rollable along a surface on the wheels of the second wheel base. The second wheel base is foldably coupled to the first wheel base. The first and second wheel bases are foldable from an extended position where the wheels of both the first and second wheel base generally reside on the same plane to a folded position where the wheels of the first and second wheel bases do not generally reside on the same plane. In an extended position, a laser system module is movable between the first wheel base and the second wheel base.
In another aspect of the invention, a cart includes a first wheel base including wheels. The cart is rollable along a surface on the wheels of the first wheel base. The cart includes a second wheel base including wheels. The cart is rollable along a surface on the wheels of the second wheel base. The second wheel base is foldably coupled to the first wheel base. The first and second wheel bases are foldable from an extended position where the wheels of both the first and second wheel base generally reside on the same plane to a folded position where the wheels of the first and second wheel bases do not generally reside on the same plane.
In another aspect, the invention includes a method for moving a load on a cart over a surface obstacle. The method includes unfolding a first wheel base from a folded position to an unfolded position with respect to a second wheel base. The second wheel base has wheels residing on a surface on a first side of a surface obstacle. The second wheel base supports a load. In the unfolded position, wheels of the first wheel base reside on a surface on a second side of a surface obstacle opposite the first side. The method also includes moving the load from the second wheel base to be supported by the first wheel base and folding the second wheel base from the unfolded position to a folded position with respect to the first wheel base.